1. Field of the Invention
The present invention relates generally to communication networks, and more specifically, to the discovery of routes used by data transmitted over such networks.
2. Description of Related Art
Communication networks typically include a number of interconnected communication devices. Connections among the devices in some communication networks are accomplished through physical wires or optical links. Such networks may be referred to as “wired” networks. Connections among the devices in other communication networks are accomplished through radio, infrared, or other wireless links. Such networks may be referred to as “wireless” networks.
Communication messages (e.g., chunks of data, such as data packets) sent across communication networks may be intercepted. Intercepted messages may yield valuable information, and the process of intercepting and analyzing messages may be referred to as “traffic analysis.” In general, traffic analysis seeks to understand something about the message traffic by passively observing the traffic and analyzing that traffic to extract information. To guard against unwanted traffic analysis, messages are typically encrypted. For example, both the content and the destination of a message could be obscured through encryption.
In some situations, however, it may still be desirable to monitor traffic flow and discover routes used in a communication network (i.e., the “topology” of the network). Accordingly, there is a need to monitor traffic flow and discover routes even when identifying information associated with the messages is encrypted.